DCP 3

How many valence electrons are in an atom of each element in Group 15 in the periodic table? (Valence Electrons = Top of Periodic Table)

• 33
• 15
• 5
• 7

Which of these statements about the mass of subatomic particles is true?

• The mass of a proton is the same as the mass of an electron.

• The mass of a proton is much greater than the mass of an electron.

• The mass of a neutron is much greater than the mass of a proton,

How many valence electrons does an atom of Oxygen (O) have?

• 16
• 8
• 6
• 15

Which two elements on the periodic table are in the same period? (Period = Horizontal)

• Sn and Rb
• F and Cl
• K and Ba
• Se and Te

A student is studying calcium, a highly reactive element that humans need for strong bones. Which characteristic of calcium is most closely related to its chemical reactivity? (Reactivity = Valence Electrons)

• The 20 protons in each atom of calcium
• The density of calcium, which is 1.54 g/cm^3
• The atomic mass of calcium, which is 40.078 amu
• The 2 valence electrons in each atom of calcium

Which statements correctly compare metals and nonmetals?

• Metals tend to be good conductors of thermal energy. Nonmetals tend to be good insulators of thermal energy.
• Metals are dull and brittle. Nonmetals are shiny and maleable.

Which unknown substance is most likely sulfur?

(Density = Mass/Volume)

• Substance 1
• Substance 2
• Substance 3
• Substance 4

Which unknown substance is most likely sulfur?

(Density = Mass/Volume)

• Substance 1
• Substance 2
• Substance 3
• Substance 4

How many neutrons are in the nucleus of a potassium (K) atom with a mass number of 39? (Protons + Neutrons = Mass)

If an Arsenic (As) atom has a mass number of 75, how many neutrons are in the atom? (Protons + Neutrons = Mass)